Apparatus for burnishing aluminum die castings



Aug. 14, 1956 c, w BENEDICT 2,758,362

APPARATUS FOR BURNISHING ALUMINUM DIE CASTINGS Filed April 14,- 1955 4 Sheets-Sheet 1 BY M awry

Aug. 14, 1956 c. w. BENEDICT 2,758,362

APPARATUS FOR BURNISHING ALUMINUM DIE CASTINGS Filed April 14 1955 4 Sheet-Sheet 2 VIII/1% Zwezzfi 4/2787768-2/58728044? Aug. 14, 1956 c. w. BENEDICT 2,758,362

APPARATUS FOR BURNISHING ALUMINUM DIE CASTINGS Filed April 14, 1953 4 Sheets-Sheet 3 ga rerzee Beneakf Aug. 14, 1956 Q w, BENEDICT 2,758,362

APPARATUS FOR BURNISHING ALUMINUM DIE CASTINGS Filed April 14, 1953 4 Sheets-Sheet 4 cfi llnited States Patent APPARATUS FOR BURNISHING ALUMINUM DIE CASTINGS Clarence W. Benedict, Armonk, N. Y., assignor to Roll- Brite Corporation, White Plains, N. Y., a corporation of New York Application April 14, 1953-, Serial No. 348,657

2 Claims. (Cl. 29-90) This invention relates particularly to an apparatus for burnishing aluminum die castings, although the invention contemplates the burnishing or polishing of other metallic articles.

The invention is especially directed to the burnishing of large articles in a tumbling barrel efficiently and at low cost; and a primary object of the invention is to provide such an apparatus and method whereby the articles can be secured on a rack outside the tumbling barrel and easily and quickly inserted in and removed from the barrel all at one time so that articles can be rapidly handled and burnished.

Another object is to provide a method and apparatus of this character which shall include a novel and improved rack and a horizontal tumbling barrel having a horizontal shaft thereon upon and from which the rack can be easily slid through one end of the barrel, thereby to insure easy loading and unloading of the rack with all of the articles thereon into and from the barrel re spectively, and permitting handling of the rack and all of the articles thereon as a unit for subsequent treatment of the articles such as washing and drying thereof.

A further object is to provide in apparatus of the character described a novel and improved article rack comprising a central tubular body section or support and means for mounting the articles in radial relation to said support, in combination with a tumbling barrel rotatable about a horizontal axis having one end removable and having a coaxial shaft on which said central tubular body section or support can be slid endwise and mounted in the barrel for rotation with the barrel or relatively thereto as desired.

Other objects are to provide such a rack whereby different articles can be mounted in different angular relations to the axis of rotation of the barrel for most effective burnishing operations in the barrel and with the articles arranged in tiers and some thereof close to said axis of rotation so as to permit the racking and burnishing of more articles in a given space than has been possible heretofore; and to obtain other advantages and results that will be brought out by the following description in conjunction with the accompanying drawings in which Figure 1 is a side elevational view of a burnishing apparatus constructed in accordance with the invention and showing the removable end wall or cover of the tumbling barrel detached;

Figure 2 is an enlarged fragmentary vertical sectional view through the tumbling barrel and an article rack showing the rack being inserted into the barrel;

Figure 3 is a similar view showing the barrel with the rack completely mounted therein and with the end wall of the barrel in place;

Figure 4 is a transverse vertical sectional view approximately on the plane of the line 44 of Figure 2;

Figure 5 is an end elevational view of the tumbling barrel as shown in Figure 3 with portions broken away approximately on the plane of the line 55 of Fig. 3;

ice v Figure 5 is an end elevational view of the tumbling barrel as shown in Figure 3 with portions broken away approximately on the plane of the line 5-5 of Fig. 3;

Figure 6 is a fragmentary transverse vertical sectional view on the plane of the line 6-6 of Fig. 2;

Figure 7 is a side elevational view of an article rack and a carriage therefor by which the rack is supported during racking of the articles and thereafter transported to the tumbling barrel;

Figure 8 is a top plan view of the rack and carriage;

Figure 9 is a transverse vertical sectional view on the plane of the line 9-9 of Figure 7;

Figure 10 is a similar view on the plane of the line 1tl10 of Fig. 7;

Figure 11 is a like view on the plane of the line 1111 of Fig. 7;

Figure 12 is an enlarged fragmentary sectional view approximately on the plane of the line 1212 of Fig. 7;

Figure 13 is a side elevational view of another form of the article rack;

Figure 14 is a transverse vertical sectional view approximately on the plane of the line 14-14 of Fig. 13;

Figure 15 is a view similar to Fig. 14 showing another form of the rack; and

Figure 16 is a vertical sectional view through the rack and hoisting apparatus and a tank, showing the method of handling the rack and articles for washing of the articles.

Specifically describing the embodiment of the invention illustrated in Figures 1 to 12 inclusive, the reference character A designates a tumbling barrel, preferably polygonal in cross section and mounted to rotate about a horizontal axis. As shown, the barrel has a closed end 1 which is bolted to a plate 2 that is keyed or otherwise fast secured on a shaft 3 which is journaled in suitable bearings 4. The shaft 3 is driven through gearing generally designated 5 from a countershaft 6 which has a belt and pulley connection 7 with the drive shaft 8 of an electric motor 9.

A rack-supporting shaft 10 is rigidly mounted at one end on the wall 1 of the barrel as indicated at 11. The shaft is coaxial with the barrel and normally the other end of the shaft is seated in a recess 12 on the inner surface of the end wall or cover 13 of the barrel which is separably clamped on the end of the barrel by means of swing bolts 14 of known construction. Preferably the shaft 10 is hollow for lightness in weight. To facilitate handling of the cover 13, handles 15 are provided on the outer surface of the cover.

The barrel also has an opening 16 in its side wall for the charging of the barrel with tumbling balls and water or other suitable liquid, and the opening is normally closed by a door 17 (see Fig. 5) that is clamped in closed position by swing bolts 18.

In accordance with the invention, the articles to be burnished are mounted on a rack B outside the barrel, and as shown the rack includes a central tubular body section or support 19 of a diameter slightly greater than that of the shaft 10 of the barrel and of a length approximately equal to the distance between the solid end wall 1 and the end cover 13 of the barrel. The articles to be burnished are mounted or racked on this body section by means the form of which depends upon the shape and structure of the articles.

In Figs. 1 to 12 inclusive the rack is designed for supporting aluminum nozzles C for vacuum cleaners, and the rack has a plurality of radial posts 20 rigidly mounted thereon, there being four pairs of posts, the posts of each pair being spaced apart longitudinally of the body section. On each pair of posts are shown two rails 21 spaced apart in a direction outwardly from the axis of the body section, and on each rail are secured a plurality of brackets 22, each for one of the articles C. Each bracket comprises a main tubular cylindrical portion 23 (see Fig. 12) of a diameter to fit a socket D in the article C, said main section having a leg 24 that is bolted to the corresponding rail 21. The main section 23 has a screw-threaded opening 24a to receive a screw 25 between the head of which and the base of a recess E in the article is a washer plate 26, whereby the article C is firmly secured on the bracket. Preferably the articles are arranged in tiers as shown so that a large number of them can be handled at the same time in the tumbling barrel, the inner-most tiers being disposed close to the axis of the body section.

For supporting the rack during the mounting of the articles thereon and transporting the rack to the barrel, a wheeled carriage F is provided and includes a base frame G having a vertical post H from which projects a horizontal arm I that is of a diameter less than the diameter of the body section 19 of the rack. During mounting of the articles on the rack the rack is supported on the arm I as shown in Figs. 7 and 8 and any suitable means such as a clamping screw I may be utilized to hold the rack against rotation on the arm. When it is desired to place the articles in the barrel the end cover 13 of the barrel is removed and the carriage F is rolled to bring the arm I into axial alignment with the shaft 10 of the tumbling barrel as shown in Fig. 2, whereupon the rack is slid off the arm H and on to the shaft 10.

The end cover 13 of the barrel is then clamped in barrel-closing position as shown in Figure 3, and the door 17 is removed from the opening 16 with the latter disposed above the horizontal diametral plane of the barrel as shown in Figs. 2 and 5. Then the material such as metal shot or polishing balls 27 to be used for burnishing the articles C are poured into the barrel through said opening 16, there being enough shot to completely embed the articles that are below said horizontal diametral plane of the barrel as best shown at the right hand side of Fig. 3. Then enough water or other suitable liquid is poured through the opening 16 to bring the level of the liquid 28 substantially above said diametral plane of the barrel as shown in Fig. 3. The door 17 of the opening 16 is then clamped in closing position and rotation of the barrel is started by any suitable controlling the circuit to the motor 9, or a clutch may be used in the driving mechanism. The invention contemplates rotation of the rack either with or relatively to the barrel shaft 10; but preferably the rack is rotatable with the barrel shaft and for this purpose one end of the central body section has a lug 29 rigidly secured thereon and interposed between two adjacent nuts 30 on the bolts that fasten the shaft 10 to the solid end wall 1 of the barrel (see Figs. 3 and 6). The barrel may be rotated at various speeds depending upon the nature of the articles and the results desired, but generally the barrel will be rotated at speeds between 10 and 30 revolutions per minute. As the barrel rotates the articles C are brought into frictional rubbing contact with the metal shot or polishing balls whereby the surfaces of the articles are burnished efiiciently and rapidly.

After the burnishing operation has been completed, the end cover 13 of the barrel is loosened to permit the liquid to flow out of the barrel into a suitable receptacle or trough disposed beneath the barrel but not shown in the drawings; and the shot may or may not be removed as desired. Then the end cover is entirely removed from the barrel and the rack is slid off the barrel shaft 10. Where the articles are to be subjected to subsequent treatments such as washing and drying, the body section 19 of the rack may be formed at one or both ends with transverse openings 31 through which a pin 32 may be inserted to support a hook or eye 33 by which the rack may be attached to the hook 34 of a hoisting apparatus 35. After the rack has been entirely disengaged from 4 the barrel shaft 10 it may be hoisted and then dipped into a washing tub or tank 36 as shown in Fig. 16, and then removed from the tank and transported to a drying atmosphere. If desired the rack may be rapidly spun about the axis of the hook 34 so as to cause quick throwoff of the liquid by centrifugal action. Of course, the rack might be slid from the barrel shaft directly on to the arm I of the carriage F when it is not desired to subject the articles to washing, dipping or like operations.

Racks of ditferent structure for supporting different articles can be interchangeably used, each rack having a central tubular body section like the section 19 hereinbefore described and various articles can be mounted in difierent angular relations to the axis of the body sec tion by the utilization of diiferent types of brackets. For example, Figs. 13 and 14 show a rack K wherein the body section 37 has a plurality of screw-threaded rods 33 projecting radially therefrom, each to support an article L to be burnished. In this case, each article is mounted on one of the rods 38, being held in spaced relation to the body section by a sleeve 39 and being clamped between said sleeve and a nut 40 on the end of the rod.

Figure 15 shows another form of rack wherein the body section 41 is polygonal in cross section, having a plurality of flat sides angularly related to each other. Spaced longitudinally of each of said sides are a plurality of bracket arms 42 each of which has a screw threaded opening 43 to receive a screw 44 for clamping an article M thereon.

From the foregoing it will be clear that the invention permits the burnishing of articles of widely different construction and either small or large, without any disassembly of the barrel except the application andremoval of the cover; and a large number of the articles can be inserted into the barrel at the same time and removed from the barrel simultaneously, thereby providing for rapid and relatively inexpensive handling of the articles. A relatively large number of articles can be mounted in the barrel so as to efliciently utilize the space within the barrel, and the articles can be arranged in various angular relations to the axis of rotation of the barrel by the use of different bracket arms. The articles can be assembled on the racks easily and quickly outside the barrel and the rack with the articles thereon can be quickly transported means, for example, by closing a switch (not shown) to the barrel and slid directly from the carriage on to the barrel shaft through one end of the barrel, thereby insuring a rapid loading and unloading of the barrel with a minimum of labor; and the rack with the articles thereon can be handled as a unit for various treatments of the articles. The barrel may be liquid-tight so that pressure can be developed therein if desired, such pressure expediting the burnishing operation in many cases.

The now preferred embodiment of the invention has been illustrated and described primarily for the purpose of explaining the principles of the invention, and many modifications and changes can be made in the construction of the apparatus and in the steps of the method within the spirit and scope of the invention.

What I claim is:

1. In apparatus for burnishing articles, a barrel to contain burnishing materials and mounted to rotate about a longitudinal axis, said barrel having one open end and a removable cover therefor, mounting means for an articlesupporting rack in said barrel comprising an elongated shaft mounted on the other end of the barrel and extending along the barrel coaxially therewith, an articlesupporting rack including a central body section having an opening therethrough of a cross section approximately corresponding in size and shape to the cross section of said shaft supported by said shaft and telescopically slidable onto and off the shaft through said open end of the barrel, and brackets on said body section for attaching the articles to the rack.

2. Apparatus as defined in claim 1 wherein said brackets include a plurality of article holding members mount- References Cited in the file of this patent UNITED STATES PATENTS Hart Jan. 14, 1913 Spellman Apr. 11, 1916 6 Goke et a1. Feb. 5, 1924 Abbott May 12, 1925 Fabens Mar. 29, 1932 Whitehead Apr. 24, 1951 FOREIGN PATENTS Great Britain Nov. 23, 1915 France Jan. 21, 1929 

1. IN APPARATUS FOR BURNISHING ARTICLES, A BARREL TO CONTAIN BURNISHING MATERIALS AND MOUNTED TO ROTATE ABOUT A LONGITUDINAL AXIS, SAID BARREL HAVING ONE OPEN END AND A REMOVABLE COVER THEREFOR, MOUNTING MEANS FOR AN ARTICLESUPPORTING RACK IN SAID BARREL COMPRISING AN ELONGATED SHAFT MOUNTED ON THE OTHER END OF THE BARREL AND EXTENDING ALONG THE BARREL COAXIALLY THEREWITH, AN ARTICLESUPPORTING RACK INCLUDING A CENTRAL BODY SECTION HAVING AN OPENING THERETHROUGH OF A CROSS SECTION APPROXIMATELY 